Generally speaking, the more depraved a military dictator is, the stupider his actions. This rough rule of thumb certainly seems to hold true for Than Shwe whose decision to place Burma's much-persecuted pro-democracy leader, Aung San Suu Kyi, on trial on trumped-up charges has backfired spectacularly.

If Burma's senior general hoped to sideline Suu Kyi ahead of next year's state-managed elections, the trial now under way in Insein prison is having the opposite effect. After a period in which her leadership of the National League for Democracy was increasingly questioned, Than Shwe has managed in the space of a week to re-unite the opposition and galvanise the international community in furious support of her.

What foreign secretary David Miliband calls the "show trial" in Rangoon has also drawn the spotlight back to the egregious human rights violations perpetrated by the regime in the wake of the failed 2007 uprising, known as the saffron revolution. Of grave concern is the plight of Burma's more than 2,000 political prisoners who are held in a gulag of about 100 jails and labour camps spread across the country.

A report entitled Burma's Silent Killing Fields, published last week by the Thailand-based Assistance Association for Political Prisoners (AAPP), a group comprising exiled activists and former prisoners, paints a horrific, case-by-case picture of systematic abuse including torture, deaths in custody, denial of medical assistance and a deliberate policy of transferring prisoners to remote regions to prevent family access and support.

Most of the abuse thus takes place far from the public eye and out of sight of the international community, not least because the International Committee of the Red Cross was forced to suspend prison visits in 2006. The ICRC said it was prevented from working freely; the report calls on the UN security council to insist that, at a minimum, the junta grant it unrestricted access to the gulag.

Among 127 prisoners said to be suffering from dangerously poor health are Htay Kywe, a leader of the pro-democracy 88 Generation movement held in Buthidaung prison in Arakan state. "Htay Kywe has been tortured in Buthidaung," the AAPP said. "He has also been denied food and the right to exercise. He has not been allowed to bathe regularly and has developed scabies as a result. He suffers from high blood pressure. He is currently held in solitary confinement. There is no doctor at the prison, which is over 700 miles from Yangon [Rangoon]."

Also highlighted are the cases of Hla Myo Naung of 88 Generation, held at Myitkyina prison in Kachin state, blinded in one eye, at risk of total blindness, but denied medical treatment; Su Su Nway, an NLD activist held at Kale prison in Sagaing division, who has a heart condition and cannot walk unaided, but who has no access to a doctor; and activist Myo Yan Naung Thein, who was tortured after his arrest in 2007 and is now suffering from paralysis at Thandwe prison in Arakan.

Family members told the AAPP the policy of transfers to remote parts of the country meant they could not see or aid their imprisoned relatives due to the cost of travel and the denial of necessary permits. "We could not meet her for nearly two months. Now we are worried about her health after hearing she is vomiting almost daily. She is said to have a peptic ulcer and is in solitary confinement," said the mother-in-law of Nilar Thein who is held at Thayet prison in Magwe division.

Other ongoing abuses include lack of treatment or protection from rampant malaria (the prisoners are allowed no mosquito nets), tuberculosis and HIV; imprisonment in labour camps, which is "tantamount to a death sentence"; and torture.

"Torture is state policy in Burma and common practice at interrogation centres and prisons. Common forms include sleep deprivation, beatings and stress positions ... Punishments such as solitary confinement exacerbate existing injuries," the report states. Combined with poor nutrition and hygiene, these conditions have "a severely detrimental impact on the physical and mental health of the prisoner". Such practices, it concludes, are designed "to ensure that political prisoners never leave prison".

According to Burma Campaign UK, 300,000 people so far have signed a petition calling on Ban Ki-moon, the UN secretary-general, to secure the release of all Burma's political prisoners. But the UN, like the Association of South-East Asian Nations, appears powerless to stop the horror. So, too, despite their angry protests over Suu Kyi's ordeal, do Britain, the EU and the US – although activists say western countries, and neighbouring China and India, could do much more if they really wanted to.

For many, it is already too late. Thet Win Aung, a member of the Basic Education Students Union, was jailed for 60 years, the AAPP said.

He was very badly tortured under interrogation. He was first held in Kale prison, in Sagaing, where he took part in a hunger strike calling for political prisoners' rights. He was then transferred to Khamti prison, where he contracted cerebral malaria.

He was denied medical treatment for a long time. Eventually he was transferred to Mandalay prison for treatment but it was too late. He died there in October, 2006.